Search

In this work, the competitive relationship between the double amorphous phases is systematically investigated to increase the high-temperature wear resistance of the self-lubricating TiAlSiCN coating. These double amorphous phases combine the SiN x phase with high-temperature resistance and the C-related phase with a low friction coefficient. An increase in the Si content facilitates the change in the phase composition. The resultant coating exhibits an adhesion strength of 153 N, a friction coefficient of 0.24 and a hardness of 25.24 GPa upon generation of the TiAlN(C), the SiN x and the C-related phase. In this case, the TiAlSiCN coating achieves long-term self-lubrication at high temperatures with the titanium alloy friction pair. This mechanism stems from the SiN x phase replacing the portion of the easily oxidized amorphous C-related phase, which yields an enhanced high-temperature wear resistance. The cutting distance of this TiAlSiCN is 120% higher than that of the TiAlCN during the high-speed cutting of the titanium alloy. This outcome provides an effective solution for high-temperature applications of self-lubricating coatings. • Long-term self-lubricating is remained in TiAlSiCN coating by optimal Si content. • Synergistic effect of amorphous SiN x and C-related phase is solved in TiAlSiCN. • Tool life of TiAlSiCN improved 225% by comparing with that of TiAlN. [ABSTRACT FROM AUTHOR]

The self-lubricating TiAlTaCN coating with high-temperature resistance above 800 °C is developed using magnetron sputtering. This mechanism stems from the TaN phase is easily oxidized to form a protective Ta 2 O 5 that compensates for the insufficient antioxidant capacity of Al 2 O 3. Moreover, the TaC phase, being resistant to oxidation, contributes to achieving the self-lubrication effect with amorphous C-related phases. The cutting distance of the TiAlTaCN is 250% greater than that of the TiAlCN during the high-speed cutting of titanium alloy. These results reveal the oxidation mechanism of different carbon nitrides and provide a new solution for the self-lubricating coatings applied at high temperatures. • A new high-temperature resistant (800 °C) self-lubricating (COF=0.27) TiAlTaCN nanocomposite coating was prepared. • The Ta addition inhibits the phase transition and increases the high thermal stability from 600 °C to 1000 °C. • The wear rate of the TiAlTaCN is 38.7% lower than that of the TiAlCN at 600 °C. • The cutting distance of the TiAlTaCN is 250% higher than the TiAlCN during the high-speed cutting of titanium alloy. [ABSTRACT FROM AUTHOR]